I suggest you look at the Lightheart SoLong tent. I've got a regular solo tent by them (not an extra long one), and am very happy with it --- it's sort of a hybrid between single-wall and double-wall tent, and weighs about what a typical single walled tent does. The SoLong model is just under 2 pounds, assuming you're a person who hikes with trekking poles (which are used as tent supports).

Anyway, have a look here.